Dashpot



Oct. 1'7, 1961 c. D. HOBSQN DASHPOT Filed Jan. 12. 1959 3,004,633V l DASHPOT 4(L'arroll 1). Hobson, Goshen, Ind., fassignor to "Goshen Rubber Co., flnc., Goshen, 1nd., .a corporation of Indiana Filed Jan. 12, 1959, Ser. No. 786,145 51Clams. y(Cl. 18S-$4) This invention relates generally to dashpots and more particularly to dashpots whose principal operating parts .are constructed from rubber or rubber-like material.

I In lthe ordinary `operation of an automobile, rapid braking vallowsthe 'throttle to close quickly; and quick lclosing of 'the throttle Vis vknownfto trap a gasoline-rich .mixture of air in the 'intake manifold. This rich mixture Nfrequently.causes-stalling of the engine.

l 'Heretofora stalling of automobile engines caused by 'trapping of these rich mixtures has been obviated by the incorporation of a metal dashpot with the carburetor throttle linkage. The dashpot delays closing of the .throttle until 'the rich mixture has y.had an opportunity to be evacuated 1from the manifold.

Such metal dashpots are known to contain a rubber diaphragm; .and Valthough metal, dashpots fso constructed lhave proved useful, they have lalso presented a number of difficulties v'arising from-.the use of a considerable number of meta-ljparts. In operation, certain Vparts slide against other parts and there is some tendency to sticking. Furthermore, these 'slidingparts areinclined to wear unevenly and shorten the .overall life of the dashpot. vSqueaking and .other noises also develop in use.

These prior art dashpots also present complicated 'assembly requiring special tools and crimping devices. Furthermore, due to the .metal construction, air escape 'orices change in size with -changes in temperature, thereby altering the performance -of the unit. Additionally, breakage of any part of such a dashpot requires scrapping of the entire unit. f

Therefore, a general object of the present invention is to provide an improved dashpot which overcomes the Alimitations of the prior art by having the principal operating parts made from rubber or rubber-like material.

Another object of the present invention is to provide a dashpothaving no sliding parts.

Yet another object of :the present invention is to provide a dashpot which is noiseless in operation.

.A further object of the invention is to-provide adash- .pot of simple," cnom'icafl construction and which is capable of hand assembly. e

A still further ohject of the invention is to provide a dashpot whose performance is :not `subject to pronounced lvariations resulting from changes .in temperature. i

Additional objectsA and ufeatures of the invention pertain to the particular structure and arrangements whereby the above objects are attained. Y

The structure in accordance with the invention includes a substantially rigid base of hard rubber and a exible, soft rubber, cup-like element which cooperates with the rigid base in defining a bellows chamber. This chamber is provided with a breather port and there is additionally included a bellows operating member.

The invention, both to its structure and mode of operation, Will be better understood by the reference to the following disclosure and drawings forming a part thereof wherein:

FIG. l is the side View of an automotive carburetor having aixed thereto a dashpot according to the present invention; Y

FIG. 2 is a cross-sectional view of the dashpot shown in FIG. l;

FIG. 3 is a cross-sectional view of the cupflike element of the dashpot according to the showing of FIG. 2;

ited States ate of the component parts.

resented oci. 17., 1961 ffice FIG. 4 is a cross-sectional view of the base member Ifor use'wit'hthe cup-like member of FIG. 3; and

FIG. 5 is a perspective view of a mounting lug which .may .be molded as 'an insert .in the base member shown in FIG. 4.

Referring now in detail .to the drawings, specifically to FIG. l, there is shown generally a dashpot 1'0 constructed in acoordance with a Ypreferred embodiment of 'the invention and raiiired "to an automotive carburetor Since one illustrative use of dashpot 10 is obviously in 'the art ot automotive interna-l combustion engines, herein- 'after such art will 'be used for ypurposes `of explanation and illustration Without limiting 'the applications and .uses of theinvention in any Way.

Carburetor '1Z`is fastened to and communicates with the 'intake manifold 124 df aconventional gasoline engine. Furthermore, carburetor 12 is provided with an air inlet 16, a fuel line connection 18 .and a throttle linkage il). These elements yare Well known in 'the art 'and are 'constructed .and arranged in conventional manner. Since .these elements comprise no part of the present invention, they vfvv'illnc't be described in detail. However, .secured to 'the throttle linkage L20 is an extended :arm 22 adapted 'to engage dashpot 1! `Stor purposes lwhich will be brought 'out hereinafter. u

Asbest shown in FIG. '2, the dashpot I0 includes a cup-'like element 24 which denes a bellows chamber 26. 'Since element 24 .i's necessarily liexib'le., li't is preferably made 'from some (suitable material, such as soit rubber. So fashioned, element 24 is able to take a position, such as the position shown .by dotted outlines 281, wherein the volume of vbellows charrber A26 is considerably reduced.

Element '24 is also provided with an operating ,post 3D which may contain a breather port 32, although it is recognized that ,port `may vbe provided separately ,from post .30. .llt shouldbe noted that Vpost 30 engages the headed end '34 of arm 22 across slot 36. 'Slot 36 Athus provides the valve action necessary for proper operation of the dashpot 10, and itis recognized that this valve action may be lequally well achieved Vby slott'ing .the

shoulder .38 -of post 30.

The lower Vportion Y2da of the cup-like element 24 vis `arranged to contain the Ybase 4); and to that cud, 4portion 24a Vis adapted to Yreceive base ciiibetween the shoulder 42 and the lip- 44. In order that base 4d may be secured in proper positionflip 'Mfmay advantageously terminate .in an upraised section 46, best shown in FIG. 3 which upraised jportion maybe engaged with the recess 43 provided'in base V4|). Y' Base 40 ,may conveniently be hollowed out to .form a `cavity 50 which cooperates `to further de'iine the bellows 'chamber 26. Additionally, base 4d may/'be provided with `a mounting 4lug 52, by means of which dashpot 10 may be secured to a suitable bracket in some acceptable manner as by means of the lock nut arrangement 5ft.

Since the necessary rigidity and other characteristics required of base 40 may advantageously be provided by molding base 4d from hard rubber, lug 52 may be secured to base 40 as by being molded therein as an insert. To facilitate such molding, lug S2 may include a flange S5 having a number of perforations 56 arranged circumferentially thereabout.

For purposes of providing an easy understanding of the invention, it is advantageous to provide at this juncture a functional description of the mode of operation Assuming that the position of linkage 20 shown in FIG. 1 indicates an open position of the throttle, a sudden release of the accelerator mechanism, such as might be experienced upon braking, would result in a movement of linkage 2t) in the general direction of arrow 60. Such movement would cause arm 22 to engage the post 30 of dashpot `10. Further movement of arm 22, and therefore of linkage 20, would be determined by the rate at which air could escape from chamber 26 through the port 32 and the orifice formed by slot 36. Y f. Y

As the air escapes through slot`36, bellows chamber 26 will be reduced in volumes and post 30` will be retracted into a position such as is indicated by dotted outlines 28, in which position element 24 is distorted from its original shape.

`In such manner, the throttle associated with the linkage 20 would be allowed to close in somewhat gradual manner thereby allowing proper exhausting of the intake manifold 14.

Upon reapplication of force to the linkage 20, movement thereof in the general direction of arrow 62 would occur. Thereby, retraction of arm 22 would be experienced and dashpot would, upon release of such -distorting forces, reassume the form associated with pansion of the chamber 26.

According to an important feature of the invention, the cup-like element 24 may be easily stretched by hand fin order to eiect rapid assembly to base 40. Element 24 may also be readily disassembled from base 40 by `manual stretching. This feature of the invention permits quick assembly in manuffacture and facilitates replacement of a torn or damaged part.

. The above description has been given with specific regard to the use of the dashpot of the present invention with an automobile carburetor. However, this illustrative use should not be construed as limiting `the invention to such an environment. It is realized that the invention is useful in the wide lield generally served by dashpots, among which may be numbered door checks and a variety of timing devices.

Y Furthermore, the specific example herein shown an described is illustrative only. Various changes in structure will, no doubt, occur to those skilled in the art; and these changes are to be understood as forming a part of this invention insofar as they fall Within the spirit and scope of the appended claims.

The invention is claimed as follows:

1. A dashpot comprising a substantially rigid base for attachment to a mounting structure, a flexible cup-like element of elastomeric material having an open end portion defined by a discrete peripheral Wall exibly fitting over and enclosing and engaging the peripheral surface of said base to be rigidiiied and closed thereby while permitting ready removal of the cup-like element and forming therewith a chamber with the remaining porapplicator for collapsing the collapsible wall section of the chamber, the spring constant of said elastomeric material being such as toreturn the collapsible wall section to its expanded condition upon removal of the force applicator, and a breatherV port communicating with said chamber and adaptedto be partially restricted when the force applicator is applied to the operating post and adpated to be substantially unrestricted upon removal of the force applicator from engagement of the post.

2. A dashpot comprising a substantially rigid base for attachment to a mounting structure, a exiblevcup-like element of elastomeric material having an open end portion defined by a discrete peripheral wall flexibly fitting over and enclosing and engaging the peripheral surface of said base to be rigiditied and closed thereby and forming therewithv a chamber with the remaining portion of the cup-like element forming a wall section collapsible independently of said peripheral wall and base, said peripheral wall including inwardly directed spaced ange means engaging opposite faces of said base to interlock the cup-like element with the base while permitting ready removal of the cup-like element, an operating post upstanding from the collapsible wall section of the cup-like element remote from said base and adapted to be engaged by a force applicator for collapsing the collapsible wall section of the chamber, the

vspringconstant of the `elastomeric material being suc-h as to returnpthe collapsible wall section to its expanded breather port communicating with the chamber permitting ,ingress and egress of air during movement` of the co1- lapsible wall section under inliuence of a force applicator and upon its return to expanded condition.

3. A dashpot as claimed in claimY 2, wherein the breather port extendsv axially through ysaid operating ost. p 4. A dashpot as claimed n claim 2, wherein one of said ange means and the adjacent surface of said base being provided` with mutually interlocking rib and groove means.

5. A dashpot as claimed in claim 5, wherein the base is formed of relatively hard rubber with a mounting structure molded therein, and wherein the cup-like element is formed of relatively soft rubber.

References Cited in the tile of this patent UNITED STATES PATENTS Y* Sanner e Feb. 10, 1925 `1,942,040 y wout V v- Jan. 2, 1934 2,421,585 Thiry Q ..l` June 3, 1947 2,947,509 Smitley et al. .Q T;.Aug 2, 1960 FOREIGN PATENTSA Y s 642,711 France May 6, 1928 

